~1H and ~(13)C NMR studies of TTHA complexes with diamagnetic rare earth ions

TTHA complexes with diamagnetic rare earth ions (La3+, Y3+ and Lu3+) were studied by 1H and 13C NMR spectroscopy. A symmetric structural model was suggested for La(TTHA) complex and an asymmetric model for Y(TTHA) and Lu(TTHA) complexes. The complex formation was dependent on the pH value of the solution. The interactions of La(TTHA) with the additional metal ions (La3+, Y3+ and Ca2+) were relatively weak, but relatively strong for that of Lu(TTHA) with the additional Lu3+.     

质子激发X射线荧光法测定高纯空气中痕量金属杂质Cr、Cu、Fe、Zn

本实验用质子激发X射线荧光法(简称PIXE法)测定了高纯空气中的痕量元素。空气样品用过滤法采集,将过滤装置与空气气路联结,微粒法采集在核孔滤膜上,后端接空气流量计,控制流量在0.5 L/min,采集2～4 h。然后用PIXE测定。此法适于分析微区样品中的痕量金属杂质。Cr、Fe、Cu、Zn的检测下限小于0.1ng/cm~2,标样由美国微物质公司(Micromatter Co.U.S.A.)提供。     

Water/Oil Diphasic Hydroformylation of Higher Olefins over a TPPTS-Rh/SiO_2 Catalyst

A novel TPPTS-Rh/SiO2 catalyst, prepared by directly modifying a heterogeneous high-surface-area Rh/SiO2 catalyst with water-soluble TPPTS ligands, could decrease the resistance of mass transfer in water/oil biphasic media for the hydroformylation of higher olefins. The catalytic performance for hydroformylation on this biphasic TPPTS-Rh/SiO2 catalyst system was higher than those of the traditional biphasic HRhCO(TPPTS)3 systems, owing to the chemical bonds between the highly dispersed Rh metal particles and the TPPTS ligands. The catalyst system is applicable for hydroformylation of higher olefins such as 1-dodecene.     

铜及氧化铜对煤燃烧过程多环芳烃排放的影响

在实验管式炉上研究了金属铜和氧化铜对烟煤燃烧过程中PAHs生成的影响。采用气相色谱分析PAHs。实验结果表明，铜会促进PAHs的生成，而且主要是促进中高分子量PAHs的生成，这是由于铜为PAHs的合成提供了大量的活性反应中心。另一方面氧化铜对PAHs的合成和裂解具有双重催化效果，从而显著增加了中分子量PAHs的排放。在800 ℃以下，添加铜和氧化铜都减小了PAHs排放的毒性当量。在900 ℃以上，添加铜增大了PAHs排放的毒性当量。添加氧化铜时与添加铜时的规律类似，但是在1100℃以上，PAHs排放的毒性当量要比不添加时小。     

A Practical Synthesis of 1—Oxo—1,2,3,4—tetrahydroisoquinoline—3—carboxylic Acid Esters

A practical synthetic method for methyl 1-oxo-1,2,3,4-tetrahy-droisoquinoline3-3carboxylate was developed by menas of triphosgene,Several analogues were prepared by this new method.     

A New Stigmasterol and a New Eremophilenolide from Ligularia dolichobotrys

A new stigmasterol 3β, 7α, 22-trihydoxystigmast-5-ene (1) and a new eremophilenolide 8α-methoxy-6β-angeloyloxyeremophil-7(1 l)-en-8β, 12-olide-14-oic acid (2) were isolated from Ligularia dolichobotrys Diels. Their structures were deduced on the basis of spectral data.     

Regular sets on the projective line

We show that if G is the group PL(2,q)(for q a prime-power) acting on the points of the projective line in the usual way, then for q>27 there is a set of 5 points such that no non-trivial element of G fixes .     

A Green and Facile Solid-state Synthesis Method for the Preparation of Diazenecarboxamide Azo Compounds with Potassium Ferricyanide and Sodium Hydroxide System

Eleven new-typed azo compounds were synthesized in good yields by dehydrogenating the corresponding aryl substituted semicarbazides using potassium ferricyanide and sodium hydroxide system under solid-state conditions.     

A Novel Sesquiterpene Isolated from Stereum sp. 8954

The basidiomycete Stereum sp. 8954 was collected in Xishuangbanna, Yunnan Province, and the mycelium of Stereum sp. 8954 was separated from fruit body and deposited in Laboratory for Conservation and Utilization of Bio-resources, Yunnan University. After fermentation, a novel sesquiterpene was isolated from the culture of the strain. The present paper deals with the structural elucidation of the new compound. Experimental Stereum sp. 8954 was fermented with PDA medium (10 L) at 26 oC fo…     

The Synthesis of l-Ethyl-1''''-(4-vinylbenzyl)-4, 4''''-bipyridinium Chloride and Iodide and its Electrochromic Property

A new compound 1-ethyl-1'-(4-vinylbenzyl)-4, 4'-bipyridinium chloride and iodide has been synthesized. The cyclic voltammogram and impedance spectra indicated that a layer of viologen's electrochromic (EC) film could be deposited on conductive ITO glass working electrode. With polyelectrolyte as ionic conduction layer, solid EC devices based on this compound have been assembled and their thickness was about 2.35 mm. When different voltages were added, they showed blue or violet red color. After optimization, its response time was less than 50 ms, the number of redox circulation was over 107 and the color of coloration states could be kept for 3 days. This kind of EC device can meet the demand of electronic ink.